Lithium-Stuffed Garnet Electrolytes for Dendrite-Resistant Thin Films
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Solution Overview
Problem
Current garnet materials for solid state lithium-ion batteries lack suitable morphology, conductivity, and stability for effective integration as catholytes, electrolytes, and anolytes, due to insufficient processing techniques that are incompatible with solid state battery components.
Innovation Solution
Development of novel methods for forming lithium-stuffed garnet thin films and powders with specific morphologies, conductivities, and surface properties, including reactive sintering and flux sintering, to create stable and conductive garnet materials suitable for use in solid state batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional garnet materials and processing techniques are used, then basic material structure is achieved, but insufficient conductivity and improper morphology prevent effective function in solid state batteries
Solution Approach 1:
The patent applies parameter changes by modifying processing temperatures, atmospheres, and time durations to transform garnet materials into forms with sufficient conductivity and proper morphology. Specifically, reactive sintering uses controlled temperature ranges (900-1100°C) and atmospheric conditions to achieve the desired material properties that conventional methods cannot attain.
Solution Approach 2:
The patent employs composite materials by creating lithium-stuffed garnet structures that combine multiple phases and compositions within the garnet lattice. This includes incorporating lithium-rich phases and stabilizing dopants to enhance conductivity while maintaining structural integrity, resulting in a composite material system with superior performance.
2Reliability
If garnet materials are prepared with higher conductivity through conventional methods, then electrical performance improves, but material stability and compatibility with battery components deteriorate
Solution Approach 1:
The patent applies local quality by creating regions with different compositions and properties within the garnet material. Specifically, lithium-stuffed regions provide high conductivity while alumina-containing regions provide structural stability and chemical inertness. This spatial differentiation allows the material to simultaneously achieve high conductivity and excellent stability.
Solution Approach 2:
The patent uses alumina as an intermediary substance that mediates between the lithium-stuffed garnet phases and external environment. The alumina layer acts as a protective barrier that maintains material stability and prevents degradation while allowing ionic conduction, thus enabling the garnet to achieve high conductivity without sacrificing stability.
3Shape
If thin film morphology is achieved through conventional processing, then integration with battery components is improved, but insufficient particle connectivity and conductivity remain
Solution Approach 1:
The patent applies preliminary action by performing reactive sintering treatments before final battery assembly. This pre-treatment establishes proper particle connectivity, density, and conductivity within the thin film structure, ensuring that the material is ready for immediate integration without requiring additional processing steps that could compromise morphology.
Solution Approach 2:
The patent utilizes phase transitions during reactive sintering to transform the garnet material from a loose powder or precursor state into a dense, interconnected thin film structure. The controlled heating induces phase changes that promote particle sintering, grain growth, and formation of continuous conductive pathways while maintaining the desired thin film geometry.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The novel garnet materials exhibit enhanced conductivity, mechanical integrity, and prevent lithium dendrite ingress, enabling improved performance and safety in solid state lithium-ion batteries.
Implementation Method 1
Garnet (e.g., Li-stuffed garnet) is a class of oxides that has the potential to be suitable for use as a catholyte, electrolyte, and, or, anolyte in an all solid state battery
Implementation Method 2
U.S. Provisional Patent Application No. 61/887,451, filed Oct. 7, 2013, entitled METHOD AND SYSTEM FOR FORMING GARNET MATERIALS WITH SINTERING PROCESS
Data Source
AI summary
Set forth herein are garnet material compositions, e.g., lithium-stuffed garnets and lithium-stuffed garnets doped with alumina, which are suitable for use as electrolytes and catholytes in solid state battery applications. Also set forth herein are lithium-stuffed garnet thin films having fine grains therein. Disclosed herein are novel and inventive methods of making and using lithium-stuffed garnets as catholytes, electrolytes and/or anolytes for all solid state lithium rechargeable batteries. Also disclosed herein are novel electrochemical devices which incorporate these garnet catholytes, electrolytes and/or anolytes. Also set forth herein are methods for preparing novel structures, including dense thin (<50 um) free standing membranes of an ionically conducting material for use as a catholyte, electrolyte, and, or, anolyte, in an electrochemical device, a battery component (positive or negative electrode materials), or a complete solid state electrochemical energy storage device. Also, the methods set forth herein disclose novel sintering techniques, e.g., for heating and/or field assisted (FAST) sintering, for solid state energy storage devices and the components thereof.